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Updated: Dec 27, 2025
Evaluation of the Interplay Between the Complement Protein C1q and Hyaluronic Acid in Promoting Cell Adhesion
Published on: June 15, 2019
Serum complement C1q level is associated with acute coronary syndrome
Xiao-Ning Ni1, Sen-Bo Yan1, Ke Zhang2
1The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital of Shandong University, Jinan, Shandong, China.
Insights
Serum complement C1q levels are lower in acute myocardial infarction patients, suggesting a role in atherosclerotic plaque instability. Lower C1q may indicate increased risk for acute coronary syndrome.
Area of Science:
- Cardiovascular Medicine
- Immunology
- Biochemistry
Background:
- The complement system is implicated in acute coronary syndrome (ACS) development.
- Complement C1q, a key component of the classical complement pathway, is linked to atherosclerosis (AS).
Purpose of the Study:
- To investigate the association between serum complement C1q levels and the severity of coronary stenosis in patients undergoing coronary arteriography.
Main Methods:
- 320 patients were stratified into non-ACS, unstable angina (UA), and acute myocardial infarction (AMI) groups.
- Coronary stenosis severity was assessed using Gensini score.
- Serum C1q levels were measured using immune transmission turbidity.
Main Results:
- Serum C1q levels were significantly lower in the AMI group compared to control and UA groups.
- A negative correlation between serum C1q and Gensini score was observed in nitrate-taking patients and non-smokers.
- Lower serum C1q was an unfavorable factor for AMI and ACS in drinking patients, though diagnostic accuracy was low.
Conclusions:
- Lower serum C1q levels in ACS, particularly AMI patients, may contribute to atherosclerotic plaque instability.
- Serum C1q, when combined with other indicators, could aid in predicting coronary stenosis risk and severity.
Background And Objectives:
The complement system plays an important role in the development of acute coronary syndrome (ACS). Complement C1q is an important initial component of the classical complement pathway and closely related to many chronic inflammatory diseases, including atherosclerosis (AS). We aimed to determine whether there was association between serum complement C1q and the severity of coronary stenosis.
Subjects And Methods:
320 patients who underwent coronary arteriography (CAG) were stratified into non-ACS group (control group, n = 74), unstable angina group (UA group, n = 197) and acute myocardial infarction group (AMI group, n = 49) according to the severity of coronary stenosis and clinical manifestations. The severity of coronary stenosis was represented in Gensini score, and serum complement C1q level was compared using immunity transmission turbidity among three groups.
Results:
The level of complement C1q in AMI group was lower significantly than control group and UA group (P < 0.05), but there was no correlation between serum complement C1q and Gensini score (β=-0.086, P = 0.125). In nitrate-taking patients, serum complement C1q had a negative association with Gensini score (r=-0.275, P = 0.001), and in non-smokers, there was also a negative correlation (β=-0.159, P = 0.036). After calibrating smoking, drinking or statins, the serum complement C1q levels of control group, UA group and AMI group decreased in sequence (P < 0.05). Logistic regression analysis showed that the decreasing of serum complement C1q was an unfavorable factor for acute myocardial infarction (OR=0.984, 95 %CI=0.972∼0.997, P = 0.015) and for ACS (OR=0.984, 95 %CI=0.971∼0.984, P = 0.025) in drinking patients. Regrettably, ROC curve suggested that the accuracy in diagnosing coronary atherosclerotic heart disease by serum complement C1q was low (AUC=0.568, 95 %CI= 0.492-0.644, P = 0.076, sensitivity 73.6 %, specificity 58.1 %).
Conclusion:
Serum complement C1q in ACS patients, in particular AMI patients, showed lower level. This finding suggests further decrease of complement C1q level in ACS patients may be a contributory factor to instability or rupture of atherosclerotic plaques. Combined with other clinical indicators, it can be helpful to predict the risk and severity of coronary stenosis.
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